A Census of Eddies in the Tropical Eastern Boundary of the Indian Ocean

Abstract

Eddies are omnipresent in the eastern boundary current regions of the world)s oceans (Bire & Wolfe, 2018;Chelton et al., 2011;Faghmous et al., 2015). They are the main source of kinetic energy in the oceans (Chelton et al., 2011), trap the eastern boundary currents near the coast (Bire & Wolfe, 2018), and contribute to mixing and transporting ocean properties over long distances (Azis Ismail & Ribbe, 2019;Faghmous et al., 2015;Henson & Thomas, 2008). The Indo-Australian Basin (IAB) located between 105°E-125°E and 6°S-20°S is the largest marginal sea along the southeastern tropical boundary of the Indian Ocean (Figure 1a). It encompasses a total area of about 2.5 million km 2 , has an average depth of about 2,500 m, and is bounded in the north by the Java and Lesser Sunda Islands and in the south by the northwest Australian shelf. The IAB comprises the sole major route for the low-latitude interbasin transport from the Pacific into the Indian Ocean which is referred to as the Indonesian Throughflow (ITF). The warm and low-salinity water transferred by the ITF into the IAB plays a key role in the Indian and Pacific Oceans) heat budget (Sprintall et al., 2014).The ITF enters the eastern edge of the IAB through an array of gaps within the Lesser Sunda Islands, namely the Lombok Strait, Ombai Strait, Sawu Sea, and Timor Passage. The outflow of the ITF along these straits induces large meanders (Feng & Wijffels, 2002) and high amplitude anticyclonic eddies (AEs) referred to as "teddies." These are eddies carrying ITF waters (Nof et al., 2002). The teddies can move westward and carry chlorophyll-rich water into the tuna-spawning zone of the IAB (Yu et al., 2015). Along the western boundary of the IAB, the mass and property exchange with the Indian Ocean takes place by means of several

Extreme Marine Heatwaves in the Southern Java during 2016

“…One of the largest MHWs in Indonesian seas from 1982 to 2021 ever recorded during 2016 occurred in southern Java. Interestingly, southern Java is well known for its productive fishing ground caused by upwelling [21][22]. Moreover, this region experiences a strong response to large-scale climate modes of El-Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD).…”

Dipole Response of Mesoscale Eddy Formation to Monsoon Transition in the Southeast Tropical Indian Ocean

“…Yang et al (2019) further pointed out that the structure of eddies varies across different monsoon seasons with significant impact on the distribution of chlorophyll. Using different algorithms, N. Zhang et al (2020), Azis Ismail et al (2021), and X. Wang et al (2021) detailed the characteristics and properties of eddies in the SETIO.…”

An Intrathermocline Eddy Observed in the Southeastern Tropical Indian Ocean

“…The southeastern tropical Indian Ocean (SETIO) is one of the regions with high mesoscale eddy activity (Azis Ismail et al., 2021; Wang et al., 2021; Yang et al., 2015). Yang et al.…”